Systems and methods for forming metal oxides using metal organo-amines and metal organo-oxides

ABSTRACT

A method of forming (and an apparatus for forming) a metal oxide layer on a substrate, particularly a semiconductor substrate or substrate assembly, using a vapor deposition process and one or more precursor compounds that include organo-amine ligands and one or more precursor compounds that include organo-oxide ligands.

FIELD OF THE INVENTION

[0001] This invention relates to methods of forming a metal oxide layeron a substrate using one or more precursor compounds that include one ormore organo-amine precursor compounds (e.g., alkylamine oralkylimino-alkylamine precursor compounds) with one or more organo-oxideprecursor compounds (e.g., alkoxide or oxo-alkoxide) precursor compoundsduring a vapor deposition process. The precursor compounds and methodsare particularly suitable for the formation of a metal oxide layers onsemiconductor substrates or substrate assemblies.

BACKGROUND OF THE INVENTION

[0002] The continuous shrinkage of microelectronic devices such ascapacitors and gates over the years has led to a situation where thematerials traditionally used in integrated circuit technology areapproaching their performance limits. Silicon (i.e., doped polysilicon)has generally been the substrate of choice, and silicon dioxide (SiO₂)has frequently been used as the dielectric material with silicon toconstruct microelectronic devices. However, when the SiO₂ layer isthinned to 1 nm (i.e., a thickness of only 4 or 5 molecules), as isdesired in the newest micro devices, the layer no longer effectivelyperforms as an insulator due to the tunneling current running throughit.

[0003] Thus, new high dielectric constant materials are needed to extenddevice performance. Such materials need to demonstrate highpermittivity, barrier height to prevent tunneling, stability in directcontact with silicon, and good interface quality and film morphology.Furthermore, such materials must be compatible with the gate material,electrodes, semiconductor processing temperatures, and operatingconditions.

[0004] High quality thin oxide films of metals, such as ZrO₂, HfO₂,Al₂O₃, and YSZ deposited on semiconductor wafers have recently gainedinterest for use in memories (e.g., dynamic random access memory (DRAM)devices, static random access memory (SRAM) devices, and ferroelectricmemory (FERAM) devices). These materials have high dielectric constantsand therefore are attractive as replacements in memories for SiO₂ wherevery thin layers are required. These metal oxide layers arethermodynamically stable in the presence of silicon, minimizing siliconoxidation upon thermal annealing, and appear to be compatible with metalgate electrodes. Specifically, for gate dielectrics, La₂O₃, HfO₂, andZrO₂ are also promising as they possess relatively high values forpermittivity and bandgap.

[0005] This discovery has led to an effort to investigate variousdeposition processes to form layers, especially dielectric layers, basedon metal oxides. Such deposition processes have included vapordeposition, metal thermal oxidation, and high vacuum sputtering. Vapordeposition processes, which includes chemical vapor deposition (CVD) andatomic layer deposition (ALD), are very appealing as they provide forexcellent control of dielectric uniformity and thickness on a substrate.But vapor deposition processes typically involve the co-reaction ofreactive metal precursor compounds with an oxygen source such as oxygenor water, either of which can cause formation of an undesirable SiO₂interfacial layer. Thus, an effort is underway to develop water- andoxygen-fi-ee vapor deposition processes.

[0006] Ritala et al., “Atomic Layer Deposition of Oxide Thin Films withMetal Alkoxides as Oxygen Sources,” SCIENCE, 288:319-321 (2000) describea chemical approach to ALD of thin oxide films. In this approach, ametal alkoxide, serving as both a metal source and an oxygen source,reacts with another metal compound such as a metal chloride or metalalkyl to deposit a metal oxide on silicon without creating aninterfacial silicon oxide layer. However, undesirable chlorine residuescan also be formed. Furthermore, zirconium and hafnium alkyls aregenerally unstable and not commercially available. They would alsolikely leave carbon in the resultant films.

[0007] Despite these continual improvements in semiconductor dielectriclayers, there remains a need for a vapor deposition process utilizingsufficiently volatile metal precursor compounds that can form a thin,high quality oxide layer, particularly on a semiconductor substrateusing a vapor deposition process.

SUMMARY OF THE INVENTION

[0008] This invention provides methods of vapor depositing a metal oxidelayer on a substrate. These vapor deposition methods involve forming thelayer by combining one or more metal organo-oxide precursor compounds(e.g., alkoxides or oxo-alkoxides) with one or more metal organo-amineprecursor compounds (e.g., alkylamines or alkylimines-alkylamines).Significantly, the methods of the present invention do not require theuse of water or a strong oxidizer, thus reducing (and typicallyavoiding) the problems of producing an undesirable interfacial oxidelayer between the desired metal oxide layer and the substrate, andoxidizing other layers beneath the top layer. Typically and preferably,the layer is a dielectric layer.

[0009] The methods of the present invention involve forming a metaloxide layer on a substrate (preferably, a semiconductor substrate orsubstrate assembly for use in manufacturing a semiconductor structure).Such methods include: providing a substrate; providing at least oneprecursor compound of the formula M¹ _(q)(O)_(x)(OR¹)_(y) (Formula I)and at least one precursor compound of the formulaM²(NR²)_(w)(NR³R⁴)_(z) (Formula II); and contacting the precursorcompounds to form a metal oxide layer on one or more surfaces of thesubstrate using a vapor deposition process. In Formulas I and II: M¹ andM² are each independently a metal; R¹, R², R³, and R⁴ are eachindependently hydrogen or an organic group; x is 0 to 4; y is 1 to 8; wis 0 to 4; z is 1 to 8; q is 1 or 2; and x, y, z, and w are dependent onthe oxidation states of M¹ and M².

[0010] In another embodiment of the present invention, a methodincludes:

[0011] providing a substrate (preferably, a semiconductor substrate orsubstrate assembly) within a deposition chamber; providing at least oneprecursor compound of the fonnula M¹ _(q)(O)_(x)(OR¹)_(y) (Formula I)and at least one precursor compound of the formulaM²(NR²)_(w)(NR³R⁴)_(z) (Formula II); vaporizing the precursor compoundsto form vaporized precursor compounds; and directing the vaporizedprecursor compounds to the substrate to form a metal oxide dielectriclayer on one or more surfaces of the substrate. In Formulas I and II: M¹and M² are each independently a metal; R¹, R², R³, and R⁴ are eachindependently hydrogen or an organic group; x is 0 to 4; y is 1 to 8; wis 0 to 4; z is 1 to 8; q is 1 or 2; and x, y, z, and w are dependent onthe oxidation states of M¹ and M².

[0012] The present invention also provides a method of manufacturing amemory device structure. The method includes: providing a substratehaving a first electrode thereon; providing at least one precursorcompound of the formula M¹ _(q)(O)_(x)(OR¹)_(y) (Formula I) and at leastone precursor compound of the formula M²(NR²)_(w)(NR³R⁴)_(z) (FormulaII); vaporizing the precursor compounds to form vaporized precursorcompounds; directing the vaporized precursor compounds to the substrateto form a metal oxide dielectric layer on the first electrode of thesubstrate; and forming a second electrode on the dielectric layer. InFormulas I and II: M¹ and M² are each independently a metal; R¹, R², R³,and R⁴ are each independently hydrogen or an organic group; x is 0 to 4;y is 1 to 8; w is 0 to 4; z is 1 to 8; q is 1 or 2; and x, y, z, and ware dependent on the oxidation states of M¹ and M².

[0013] Also provided is a vapor deposition apparatus that includes: avapor deposition chamber having a substrate positioned therein; one ormore vessels comprising one or more precursor compounds of the formulaM¹ _(q)(O)_(x)(OR¹)_(y) (Formula I); and one or more vessels comprisingone or more one precursor compounds of the formulaM²(NR²)_(w)(NR³R⁴)_(z) (Formula II). In Formulas I and II: M¹ and M² areeach independently a metal; R¹, R², R³, and R⁴ are each independentlyhydrogen or an organic group; x is 0 to 4; y is 1 to 8; w is 0 to 4; zis 1 to 8; q is 1 or 2; and x, y, z, and w are dependent on theoxidation states of M¹ and M².

[0014] The methods of the present invention can utilize a chemical vapordeposition (CVD) process, which can be pulsed, or an atomic layerdeposition (ALD) process (a self-limiting vapor deposition process thatincludes a plurality of deposition cycles, typically with purgingbetween the cycles). Preferably, the methods of the present inventionuse ALD. For certain ALD processes, the precursor compounds can bealternately introduced into a deposition chamber during each depositioncycle.

[0015] The present invention further provides a precursor compositioncomprising one or more precursor compounds of Formula I above and one ormore precursor compounds of Formula H above.

[0016] “Semiconductor substrate” or “substrate assembly” as used hereinrefers to a semiconductor substrate such as a base semiconductor layeror a semiconductor substrate having one or more layers, structures, orregions formed thereon. A base semiconductor layer is typically thelowest layer of silicon material on a wafer or a silicon layer depositedon another material, such as silicon on sapphire. When reference is madeto a substrate assembly, various process steps may have been previouslyused to form or define regions, junctions, various structures orfeatures, and openings such as capacitor plates or barriers forcapacitors.

[0017] “Layer” as used herein refers to any metal oxide layer that canbe formed on a substrate from the precursor compounds of this inventionusing a vapor deposition process. The term “layer” is meant to includelayers specific to the semiconductor industry, such as “barrier layer,”“dielectric layer,” and “conductive layer.” (The term “layer” issynonymous with the term “film” frequently used in the semiconductorindustry.) The term “layer” is also meant to include layers found intechnology outside of semiconductor technology, such as coatings onglass.

[0018] “Precursor compound” as used herein refers to a metal-containingcompound capable of forming, either alone or with other precursorcompounds, a metal oxide layer on a substrate in a vapor depositionprocess.

[0019] “Deposition process” and “vapor deposition process” as usedherein refer to a process in which a metal oxide layer is formed on oneor more surfaces of a substrate (e.g., a doped polysilicon wafer) fromvaporized precursor compound(s). Specifically, one or moremetal-containing precursor compounds are vaporized and directed to oneor more surfaces of a heated substrate (e.g., semiconductor substrate orsubstrate assembly) placed in a deposition chamber. These precursorcompounds form (e.g., by reacting or decomposing) a non-volatile, thin,uniform, metal oxide layer on the surface(s) of the substrate. For thepurposes of this invention, the term “vapor deposition process” is meantto include both chemical vapor deposition processes (including pulsedchemical vapor deposition processes) and atomic layer depositionprocesses.

[0020] “Chemical vapor deposition” (CVD) as used herein refers to avapor deposition process wherein the desired layer is deposited on thesubstrate from vaporized metal precursor (i.e., metal-containingprecursor) compounds (and any optional reaction gases used) within adeposition chamber with no effort made to separate the reactioncomponents. In contrast to a “simple” CVD process that involves thesubstantial simultaneous use of the precursor compounds and any reactiongases, “pulsed” CVD alternately pulses these materials into thedeposition chamber, but does not rigorously avoid intermixing of theprecursor and reaction gas streams, as is typically done in atomic layerdeposition or ALD (discussed in greater detail below).

[0021] “Atomic layer deposition” (ALD) as used herein refers to a vapordeposition process in which numerous consecutive deposition cycles areconducted in a deposition chamber. Typically, during each cycle themetal precursor is chemisorbed to the substrate surface; excessprecursor is purged out; a subsequent precursor an(/or reaction gas isintroduced to react with the chemisorbed layer; and excess reaction gas(if used) and by-products are removed. As compared to the one cyclechemical vapor deposition (CVD) process, the longer duration multi-cycleALD process allows for improved control of layer thickness byself-limiting layer growth and minimizing detrimental gas phasereactions by separation of the reaction components. The term “atomiclayer deposition” as used herein is also meant to include the relatedterms “atomic layer epitaxy” (ALE), molecular beam epitaxy (MBE), gassource MBE, organometallic MBE, and chemical beam epitaxy when performedwith alternating pulses of precursor compound(s), reaction gas(es), andpurge (i.e., inert carrier) gas.

[0022] “Chemisorption” as used herein refers to the chemical adsorptionof vaporized reactive precursor compounds on the surface of a substrate.The adsorbed species are irreversibly bound to the substrate surface asa result of relatively strong binding forces characterized by highadsorption energies (e.g., >30 kcal/mol), comparable in strength toordinary chemical bonds. The chemisorbed species typically form amononolayer on the substrate surface. (See “The Condensed ChemicalDictionary”, 10th edition, revised by G. G. Hawley, published by VanNostrand Reinhold Co., New York, 225 (1981)). The technique of ALD isbased on the principle of the formation of a saturated monolayer ofreactive precursor molecules by chemisorption. In ALD one or moreappropriate precursor compounds or reaction gases are alternatelyintroduced (e.g., pulsed) into a deposition chamber and chemisorbed ontothe surfaces of a substrate. Each sequential introduction of a reactivecompound (e.g., one or more precursor compounds and one or more reactiongases) is typically separated by an inert carrier gas purge. Eachprecursor compound co-reaction adds a new atomic layer to previouslydeposited layers to form a cumulative solid layer. The cycle isrepeated, typically for several hundred times, to gradually form thedesired layer thickness. It should be understood that ALD canalternately utilize one precursor compound, which is chemisorbed, andone reaction gas, which reacts with the chemisorbed species.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIGS. 1-3 are exemplary capacitor constructions.

[0024]FIG. 4 is a perspective view of a vapor deposition coating systemsuitable for use in the method of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0025] The present invention provides methods of forming a metal oxidelayer (preferably, a mixed metal oxide layer) on a substrate (preferablya semiconductor substrate or substrate assembly) using one or moreprecursor compounds of the formula M¹ _(q)(O)_(x)(OR¹)_(y) (Formula I)with one or more metal precursor compounds of the formulaM²(NR²)_(w)(NR³R⁴)_(z) (Formula II). In Formulas I and II: M¹ and M² areeach independently any metal (main group, transition metal, lanthanide);each R is independently hydrogen or an organic group; x is 0 to 4(preferably, 0 to 2); y is 1 to 8 (preferably, 2 to 6); w is 0 to 4(preferably, 0 to 2); z is 1 to 8 (preferably, 2 to 6); q is 1 or 2(preferably, 1); and x, y, and z are dependent on the oxidation state ofM¹ and M².

[0026] The metal oxide layer may include one or more different metalsand is typically of the formula M_(n)O_(m) (Formula III), wherein M canbe one or more of M¹ and M² as defined above (i.e., the oxide can be asingle metal oxide or a mixed metal oxide). Preferably, the metal oxidelayer is a mixed metal oxide (i.e., includes two or more differentmetals). More preferably, the metal oxide layer includes two differentmetals.

[0027] For certain embodiments, the metals of the compounds of FormulasI and II are the same (i.e., M¹=M²). When such compounds are used in anALD process, the growth rate per cycle may be nearly twice that oftypical ALD processes involving a single metal precursor and anoxidizing gas.

[0028] If the metal oxide layer includes two or more different metals,the metal oxide layer can be in the form of alloys, solid solutions, ornanolaminates. Preferably, these have dielectric properties. The metaloxide layer (particularly if it is a dielectric layer) preferablyincludes one or more of ZrO₂, HfO₂, Ta₂O₃, Al₂O₃, TiO₂, and an oxide ofa lanthanide.

[0029] The substrate on which the metal oxide layer is formed ispreferably a semiconductor substrate or substrate assembly. Any suitablesemiconductor material is contemplated, such as for example,conductively doped polysilicon (for this invention simply referred to as“silicon”). A substrate assembly may also contain a layer that includesplatinum, iridium, rhodium, ruthenium, ruthenium oxide, titaniumnitride, tantalum nitride, tantalum-silicon-nitride, silicon dioxide,aluminum, gallium arsenide, glass, etc., and other existing orto-be-developed materials used in semiconductor constructions, such asdynamic random access memory (DRAM) devices and static random accessmemory (SRAM) devices, for example.

[0030] Substrates other than semiconductor substrates or substrateassemblies can be used in methods of the present invention. Theseinclude, for example, fibers, wires, etc. If the substrate is asemiconductor substrate or substrate assembly, the layers can be formeddirectly on the lowest semiconductor surface of the substrate, or theycan be formed on any of a variety of the layers (i.e., surfaces) as in apatterned wafer, for example.

[0031] The precursor compounds described herein may include a widevariety of metals. As used herein, “metal” includes all metals of theperiodic table (including main group metals, transition metals,lanthanides, actinides) as well as metalloids or semimetals. For certainmethods of the present invention, preferably, each metal M is selectedfrom the group of metals of Groups IIIB (Sc, Y), IVB (Ti, Zr, Hf), VB(V, Nb, Ta), VIB (Cr, Mo, W), VIIB (Mn, Tc, Re), IIIA (Al, Ga, In, Tl),IVA (Si, Ge, Sn, Pb), and the lanthanides (La, Ce, Pr, etc.), which arealso referred to as Groups 3-7, 13, 14, the lanthanides of the PeriodicChart. More preferably, M is selected from the group of Y, La, Pr, Nd,Gd, Ti, Zr, Hf, Nb, Ta, Si, and Al.

[0032] The precursor compounds useful in this invention are of theformulas M¹(O)_(x)(OR¹)_(y) (Formula I) and M²(NR²)_(w)(NR³R⁴)_(z)(Formula I), wherein each R is independently hydrogen or an organicgroup. As used herein, the term “organic group” is used for the purposeof this invention to mean a hydrocarbon group that is classified as analiphatic group, cyclic group, or combination of aliphatic and cyclicgroups (e.g., alkaryl and aralkyl groups). In the context of the presentinvention, suitable organic groups for precursor compounds of thisinvention are those that do not interfere with the formation of a metaloxide layer using vapor deposition techniques. In the context of thepresent invention, the term “aliphatic group” means a saturated orunsaturated linear or branched hydrocarbon group. This term is used toencompass alkyl, alkenyl, and alkynyl groups, for example. The term“alkyl group” means a saturated linear or branched monovalenthydrocarbon group including, for example, methyl, ethyl, n-propyl,isopropyl, t-butyl, amyl, heptyl, and the like. The term “alkenyl group”means an unsaturated, linear or branched monovalent hydrocarbon groupwith one or more olefinically unsaturated groups (i.e., carbon-carbondouble bonds), such as a vinyl group. The term “alkynyl group” means anunsaturated, linear or branched monovalent hydrocarbon group with one ormore carbon-carbon triple bonds. The term “cyclic group” means a closedring hydrocarbon group that is classified as an alicyclic group,aromatic group, or heterocyclic group. The term “alicyclic group” meansa cyclic hydrocarbon group having properties resembling those ofaliphatic groups. The term “aromatic group” or “aryl group” means amono- or polynuclear aromatic hydrocarbon group. The term “heterocyclicgroup” means a closed ring hydrocarbon in which one or more of the atomsin the ring is an element other than carbon (e.g., nitrogen, oxygen,sulfur, etc.).

[0033] As a means of simplifying the discussion and the recitation ofcertain terminology used throughout this application, the terms “group”and “moiety” are used to differentiate between chemical species thatallow for substitution or that may be substituted and those that do notso allow for substitution or may not be so substituted. Thus, when theterm “group” is used to describe a chemical substituent, the describedchemical material includes the unsubstituted group and that group withnonperoxidic O, N, Si, F, or S atoms, for example, in the chain as wellas carbonyl groups or other conventional substituents. Where the term“moiety” is used to describe a chemical compound or substituent, only anunsubstituted chemical material is intended to be included. For example,the phrase “alkyl group” is intended to include not only pure open chainsaturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl,t-butyl, and the like, but also alkyl substituents bearing furthersubstituents known in the art, such as hydroxy, alkoxy, alkylsulfonyl,halogen atoms, cyano, nitro, amino, carboxyl, etc. Thus, “alkyl group”includes ether groups, haloalkyls, nitroalkyls, carboxyalkyls,hydroxyalkyls, sulfoalkyls, etc. On the other hand, the phrase “alkylmoiety” is limited to the inclusion of only pure open chain saturatedhydrocarbon alkyl substituents, such as methyl, ethyl, propyl, t-butyl,and the like.

[0034] For all the precursor compounds of this invention, each R isindependently and preferably hydrogen or an organic group, morepreferably a (C1-C10) organic group, even more preferably a (C1-C8)organic group, even more preferably a (C1-C6) organic group, and evenmore preferably a “lower” (i.e., C1-C4) organic group. Even morepreferably, each of these organic groups is an alkyl group. Mostpreferably, each organic group is an organic moiety, and preferably, analkyl moiety.

[0035] In certain embodiments, the carbon atoms of the R groups areoptionally replaced by or substituted with silicon, fluorine, oxygen,and/or nitrogen atoms or groups containing such atoms. Thus, siloxidesare within the scope of Formula I and silylated amines and silylatedimine-amines are within the scope of Formula II.

[0036] For the compounds of Formula I, M¹ _(q)(O)_(x)(OR¹)_(y), each R¹is preferably (C1-C6) organic group. Examples of suitable precursorcompounds include tetrakis(t-butoxide) hafnium, tetrakis(isopropoxy)titanium, and penta(ethoxy) tantalum. Such compounds are eithercommercially available from sources such as Sigma Aldrich, or they canbe prepared using standard techniques (e.g., by alcoholysis of metalalkyl amides).

[0037] For the compounds of Formula II, M²(NR²)_(w)(NR³R⁴)_(z), R², R³,and R⁴ are each preferably a (C1-C6) organic group. Examples of suitableprecursor compounds include tetrakis(dimethylamino) titanium,tetrakis(dimethylamino) hafnium, tetrakis(ethylmethylamino) hafnium, andAl (NMe₂)₂(N(Me)CH₂CH₂NMe₂). Such compounds are either commerciallyavailable from sources such as Strem Chemical Co., or they can beprepared using standard techniques (e.g., by reacting metal chlorideswith the corresponding lithium dialkyl amides).

[0038] Various precursor compounds can be used in various combinations,optionally with one or more organic solvents (particularly for CVDprocesses), to form a precursor composition. The precursor compounds maybe liquids or solids at room temperature (preferably, they are liquidsat the vaporization temperature). Typically, they are liquidssufficiently volatile to be employed using known vapor depositiontechniques. However, as solids they may also be sufficiently volatilethat they can be vaporized or sublimed from the solid state using knownvapor deposition techniques. If they are less volatile solids, they arepreferably sufficiently soluble in an organic solvent or have meltingpoints below their decomposition temperatures such that they can be usedin flash vaporization, bubbling, microdroplet formation techniques, etc.Herein, vaporized precursor compounds may be used either alone oroptionally with vaporized molecules of other precursor compounds oroptionally with vaporized solvent molecules, if used. As used herein,“liquid” refers to a solution or a neat liquid (a liquid at roomtemperature or a solid at room temperature that melts at an elevatedtemperature). As used herein, “solution” does not require completesolubility of the solid but may allow for some undissolved solid, aslong as there is a sufficient amount of the solid delivered by theorganic solvent into the vapor phase for chemical vapor depositionprocessing. If solvent dilution is used in deposition, the total molarconcentration of solvent vapor generated may also be considered as ainert carrier gas.

[0039] The solvents that are suitable for this application (particularlyfor a CVD process) can be one or more of the following: aliphatichydrocarbons or unsaturated hydrocarbons (C3-C20, and preferably C5-C10,cyclic, branched, or linear), aromatic hydrocarbons (C5-C20, andpreferably C5-C10), halogenated hydrocarbons, silylated hydrocarbonssuch as alkylsilanes, alkylsilicates, ethers, polyethers, thioethers,esters, lactones, ammonia, amides, amines (aliphatic or aromatic,primary, secondary, or tertiary), polyamines, nitrites, cyanates,isocyanates, thiocyanates, silicone oils, alcohols, or compoundscontaining combinations of any of the above or mixtures of one or moreof the above. The compounds are also generally compatible with eachother, so that mixtures of variable quantities of the precursorcompounds will not interact to significantly change their physicalproperties.

[0040] For this invention, preferably no reaction gas is employed tominimize oxidation of the substrate (typically silicon) to its oxide(typically silicon dioxide). That oxidizing process can also causedetrimental oxidation to other substrates such as metal electrodes ornitride barriers. Also, as is known in the art some layers can bepervious to oxidizing gases and cause detrimental oxidation of a layerbelow the top substrate layer.

[0041] The precursor compounds can be vaporized in the presence of aninert carrier gas if desired. Additionally, an inert carrier gas can beused in purging steps in an ALD process. The inert carrier gas istypically selected from the group consisting of nitrogen, helium, argon,and combinations thereof. In the context of the present invention, aninert carrier gas is one that does not interfere with the formation ofthe metal oxide layer. Whether done in the presence of a inert carriergas or not, the vaporization is preferably done in the absence of oxygento avoid oxygen contamination of the layer (e.g., oxidation of siliconto form silicon dioxide).

[0042] The deposition process for this invention is a vapor depositionprocess. Vapor deposition processes are generally favored in thesemiconductor industry due to the process capability to quickly providehighly conformal layers even within deep contacts and other openings.Chemical vapor deposition (CVD) and atomic layer deposition (ALD) aretwo vapor deposition processes often employed to form thin, continuous,uniform, metal oxide (preferably dielectric) layers onto semiconductorsubstrates. Using either vapor deposition process, typically one or moreprecursor compounds are vaporized in a deposition chamber and optionallycombined with one or more reaction gases to form a metal oxide layeronto a substrate. It will be readily apparent to one skilled in the artthat the vapor deposition process may be enhanced by employing variousrelated techniques such as plasma assistance, photo assistance, laserassistance, as well as other techniques.

[0043] The final layer (preferably, a dielectric layer) formedpreferably has a thickness in the range of about 10 Å to about 500 Å.More preferably, the thickness of the metal oxide layer is in the rangeof about 30 Å to about 80 Å.

[0044] In most vapor deposition processes, the precursor compound(s) aretypically reacted with an oxidizing or reducing reaction gas at elevatedtemperatures to form the metal oxide layer. However, in the practice ofthis invention, no such reaction gas is needed because the precursor ofFormula I provides the oxygen to the film formed. However, oxidizinggases, such as O₂, O₃, H₂O, H₂O₂, and N₂O can be used if desired.

[0045] Chemical vapor deposition (CVD) has been extensively used for thepreparation of metal oxide layers, such as dielectric layers, insemiconductor processing because of its ability to provide highlyconformal and high quality dielectric layers at relatively fastprocessing times. The desired precursor compounds are vaporized and thenintroduced into a deposition chamber containing a heated substrate withoptional reaction gases and/or inert carrier gases. In a typical CVDprocess, vaporized precursors are contacted with reaction gas(es) at thesubstrate surface to form a layer (e.g., dielectric layer). The singledeposition cycle is allowed to continue until the desired thickness ofthe layer is achieved.

[0046] Typical CVD processes generally employ precursor compounds invaporization chambers that are separated from the process chamberwherein the deposition surface or wafer is located. For example, liquidprecursor compounds are typically placed in bubblers and heated to atemperature at which they vaporize, and the vaporized liquid precursorcompound is then transported by an inert carrier gas passing over thebubbler or through the liquid precursor compound. The vapors are thenswept through a gas line to the deposition chamber for depositing alayer on substrate surface(s) therein. Many techniques have beendeveloped to precisely control this process. For example, the amount ofprecursor material transported to the deposition chamber can beprecisely controlled by the temperature of the reservoir containing theprecursor compound and by the flow of an inert carrier gas bubbledthrough or passed over the reservoir.

[0047] Preferred embodiments of the precursor compounds described hereinare particularly suitable for chemical vapor deposition (CVD). Thedeposition temperature at the substrate surface is preferably held at atemperature in a range of about 100° C. to about 600° C., morepreferably in the range of about 200° C. to about 500° C. The depositionchamber pressure is preferably maintained at a deposition pressure ofabout 0.1 torr to about 10 torr. The partial pressure of precursorcompounds in the inert carrier gas is preferably about 0.001 torr toabout 10 torr.

[0048] Several modifications of the CVD process and chambers arepossible, for example, using atmospheric pressure chemical vapordeposition, low pressure chemical vapor deposition (LPCVD), plasmaenhanced chemical vapor deposition (PECVD), hot wall or cold wallreactors or any other chemical vapor deposition technique. Furthermore,pulsed CVD can be used, which is similar to ALD (discussed in greaterdetail below) but does not rigorously avoid intermixing of percursor andreactant gas streams. Also, for pulsed CVD, the deposition thickness isdependent on the exposure time, as opposed to ALD, which isself-limiting (discussed in greater detail below).

[0049] A typical CVD process may be carried out in a chemical vapordeposition reactor, such as a deposition chamber available under thetrade designation of 7000 from Genus, Inc. (Sunnyvale, Calif.), adeposition chamber available under the trade designation of 5000 fromApplied Materials, Inc. (Santa Clara, Calif.), or a deposition chamberavailable under the trade designation of Prism from Novelus, Inc. (SanJose, Calif.). However, any deposition chamber suitable for performingCVD may be used.

[0050] Alternatively, and preferably, the vapor deposition processemployed in the methods of the present invention is a multi-cycle ALDprocess. Such a process is advantageous (particularly over a CVDprocess) in that in provides for optimum control of atomic-levelthickness and uniformity to the deposited layer (e.g., dielectric layer)and to expose the metal precursor compounds to lower volatilization andreaction temperatures to minimize degradation. Typically, in an ALDprocess, each reactant is pulsed sequentially onto a suitable substrate,typically at deposition temperatures of about 25° C. to about 400° C.(preferably about 150° C. to about 300° C.), which is generally lowerthan presently used in CVD processes. Under such conditions the filmgrowth is typically self-limiting (i.e., when the reactive sites on asurface are used up in an ALD process, the deposition generally stops),insuring not only excellent conformality but also good large areauniformity plus simple and accurate thickness control. Due to alternatedosing of the precursor compounds and/or reaction gases, detrimentalvapor-phase reactions are inherently eliminated, in contrast to the CVDprocess that is carried out by continuous coreaction of the precursorsand/or reaction gases. (See Vehkamäki et al, “Growth of SrTiO₃ andBaTiO₃ Thin Films by Atomic Layer Deposition,” Electrochemical andSolid-State Letters, 2(10):504-506 (1999)).

[0051] A typical ALD process includes exposing an initial substrate to afirst chemical species (e.g., a precursor compound of Formula I) toaccomplish chemisorption of the species onto the substrate.Theoretically, the chemisorption forms a monolayer that is uniformly oneatom or molecule thick on the entire exposed initial substrate. In otherwords, a saturated monolayer. Practically, chemisorption might not occuron all portions of the substrate. Nevertheless, such an imperfectmonolayer is still a monolayer in the context of the present invention.In many applications, merely a substantially saturated monolayer may besuitable. A substantially saturated monolayer is one that will stillyield a deposited layer exhibiting the quality and/or properties desiredfor such layer.

[0052] The first species is purged from over the substrate and a secondchemical species (e.g., a different precursor compound of Formula I or aprecursor compound of Formula II) is provided to react with the firstmonolayer of the first species. The second species is then purged andthe steps are repeated with exposure of the second species monolayer tothe first species. In some cases, the two monolayers may be of the samespecies. As an option, the second species can react with the firstspecies, but not chemisorb additional material thereto. That is, thesecond species can cleave some portion of the chemisorbed first species,altering such monolayer without forming another monolayer thereon. Also,a third species or more may be successively chemisorbed (or reacted) andpurged just as described for the first and second species. Optionally,the second species (or third or subsequent) can include at least onereaction gas if desired.

[0053] Purging may involve a variety of techniques including, but notlimited to, contacting the substrate and/or monolayer with a carrier gasand/or lowering pressure to below the deposition pressure to reduce theconcentration of a species contacting the substrate and/or chemisorbedspecies. Examples of carrier gases include N₂, Ar, He, etc. Purging mayinstead include contacting the substrate and/or monolayer with anysubstance that allows chemisorption by-products to desorb and reducesthe concentration of a contacting species preparatory to introducinganother species. The contacting species may be reduced to some suitableconcentration or partial pressure known to those skilled in the artbased on the specifications for the product of a particular depositionprocess.

[0054] ALD is often described as a self-limiting process, in that afinite number of sites exist on a substrate to which the first speciesmay form chemical bonds. The second species might only bond to the firstspecies and thus may also be self-limiting. Once all of the finitenumber of sites on a substrate are bonded with a first species, thefirst species will often not bond to other of the first species alreadybonded with the substrate. However, process conditions can be varied inALD to promote such bonding and render ALD not self-limiting.Accordingly, ALD may also encompass a species forming other than onemonolayer at a time by stacking of a species, forming a layer more thanone atom or molecule thick.

[0055] The described method indicates the “substantial absence” of thesecond precursor (i.e., second species) during chemisorption of thefirst precursor since insignificant amounts of the second precursormight be present. According to the knowledge and the preferences ofthose with ordinary skill in the art, a determination can be made as tothe tolerable amount of second precursor and process conditions selectedto achieve the substantial absence of the second precursor.

[0056] Thus, during the ALD process, numerous consecutive depositioncycles are conducted in the deposition chamber, each cycle depositing avery thin metal oxide layer (usually less than one monolayer such thatthe growth rate on average is from about 0.2 to about 3.0 Angstroms percycle), until a layer of the desired thickness is built up on thesubstrate of interest. The layer deposition is accomplished byalternately introducing (i.e., by pulsing) precursor compounds into thedeposition chamber containing a semiconductor substrate, chemisorbingthe precursor compound(s) as a monolayer onto the substrate surfaces,and then reacting the chemisorbed precursor compound(s) with the otherco-reactive precursor compound(s). The pulse duration of precursorcompound(s) and inert carrier gas(es) is sufficient to saturate thesubstrate surface. Typically, the pulse duration is from about 0.1 toabout 5 seconds, preferably from about 0.2 to about 1 second.

[0057] In comparison to the predominantly thermally driven CVD, ALD ispredominantly chemically driven. Accordingly, ALD is often conducted atmuch lower temperatures than CVD. During the ALD process, the substratetemperature is maintained at a temperature sufficiently low to maintainintact bonds between the chemisorbed precursor compound(s) and theunderlying substrate surface and to prevent decomposition of theprecursor compound(s). The temperature is also sufficiently high toavoid condensation of the precursor compounds(s). Typically thesubstrate temperature is kept within the range of about 25° C. to about400° C. (preferably about 150° C. to about 300° C.), which is generallylower than presently used in CVD processes. Thus, the first species orprecursor compound is chemisorbed at this temperature. Surface reactionof the second species or precursor compound can occur at substantiallythe same temperature as chemisorption of the first precursor or, lesspreferably, at a substantially different temperature. Clearly, somesmall variation in temperature, as judged by those of ordinary skill,can occur but still be a substantially same temperature by providing areaction rate statistically the same as would occur at the temperatureof the first precursor chemisorption. Chemisorption and subsequentreactions could instead occur at exactly the same temperature.

[0058] For a typical ALD process, the pressure inside the depositionchamber is kept at about 10⁻⁴ torr to about 1 torr, preferably about10⁻⁴ torr to about 0.1 torr. Typically, the deposition chamber is purgedwith an inert carrier gas after the vaporized precursor compound(s) havebeen introduced into the chamber and/or reacted for each cycle. Theinert carrier gas(es) can also be introduced with the vaporizedprecursor compound(s) during each cycle.

[0059] The reactivity of a precursor compound can significantlyinfluence the process parameters in ALD. Under typical CVD processconditions, a highly reactive compound may react in the gas phasegenerating particulates, depositing prematurely on undesired surfaces,producing poor films, and/or yielding poor step coverage or otherwiseyielding non-uniform deposition. For at least such reason, a highlyreactive compound might be considered not suitable for CVD. However,some compounds not suitable for CVD are superior ALD precursors. Forexample, if the first precursor is gas phase reactive with the secondprecursor, such a combination of compounds might not be suitable forCVD, although they could be used in ALD. In the CVD context, concernmight also exist regarding sticking coefficients and surface mobility,as known to those skilled in the art, when using highly gas-phasereactive precursors, however, little or no such concern would exist inthe ALD context.

[0060] After layer formation on the substrate, an annealing process canbe optionally performed in situ in the deposition chamber in a nitrogenatmosphere or oxidizing atmosphere. Preferably, the annealingtemperature is within the range of about 400° C. to about 1000° C.Particularly after ALD, the annealing temperature is more preferablyabout 400° C. to about 750° C., and most preferably about 600° C. toabout 700° C. The annealing operation is preferably performed for a timeperiod of about 0.5 minute to about 60 minutes and more preferably for atime period of about 1 minute to about 10 minutes. One skilled in theart will recognize that such temperatures and time periods may vary. Forexample, furnace anneals and rapid thermal annealing may be used, andfurther, such anneals may be performed in one or more annealing steps.

[0061] As stated above, the use of the complexes and methods of formingfilms of the present invention are beneficial for a wide variety of thinfilm applications in semiconductor structures, particularly those usinghigh dielectric materials. For example, such applications includecapacitors such as planar cells, trench cells (e.g., double sidewalltrench capacitors), stacked cells (e.g., crown, V-cell, delta cell,multi-fingered, or cylindrical container stacked capacitors), as well asfield effect transistor devices.

[0062] A specific example of where a dielectric layer is formedaccording to the present invention is a capacitor construction.Exemplary capacitor constructions are described with reference to FIGS.1-3. Referring to FIG. 1, a semiconductor wafer fragment 10 includes acapacitor construction 25 formed by a method of the present invention.Wafer fragment 10 includes a substrate 12 having a conductive diffusionarea 14 formed therein. Substrate 12 can include, for example,monocrystalline silicon. An insulating layer 16, typicallyborophosphosilicate glass (BPSG), is provided over substrate 12, with acontact opening 18 provided therein to diffusion area 14. A conductivematerial 20 fills contact opening 18, with material 20 and oxide layer18 having been planarized as shown. Material 20 might be any suitableconductive material, such as, for example, tungsten or conductivelydoped polysilicon. Capacitor construction 25 is provided atop layer 16and plug 20, and electrically connected to node 14 through plug 20.

[0063] Capacitor construction 25 includes a first capacitor electrode26, which has been provided and patterned over node 20. Examplarymaterials include conductively doped polysilicon, Pt, Ir, Rh, Ru, RuO₂,IrO₂, RhO₂. A capacitor dielectric layer 28 is provided over firstcapacitor electrode 26. The materials of the present invention can beused to form the capacitor dielectric layer 28. Preferably, if firstcapacitor electrode 26 includes polysilicon, a surface of thepolysilicon is cleaned by an in situ HF dip prior to deposition of thedielectric material. An exemplary thickness for layer 28 in accordancewith 256 Mb integration is 100 Angstroms.

[0064] A diffusion barrier layer 30 is provided over dielectric layer28. Diffusion barrier layer 30 includes conductive materials such asTiN, TaN, metal silicide, or metal silicide-nitride, and can be providedby CVD, for example, using conditions well known to those of skill inthe art. After formation of barrier layer 30, a second capacitorelectrode 32 is formed over barrier layer 30 to complete construction ofcapacitor 25. Second capacitor electrode 32 can include constructionssimilar to those discussed above regarding the first capacitor electrode26, and can accordingly include, for example, conductively dopedpolysilicon. Diffusion barrier layer 30 preferably prevents components(e.g., oxygen) from diffusing from dielectric material 28 into electrode32. If, for example, oxygen diffuses into a silicon-containing electrode32, it can undesirably form SiO₂, which will significantly reduce thecapacitance of capacitor 25. Diffusion barrier layer 30 can also preventdiffusion of silicon from metal electrode 32 to dielectric layer 28.

[0065]FIG. 2 illustrates an alternative embodiment of a capacitorconstruction. Like numerals from FIG. 1 have been utilized whereappropriate, with differences indicated by the suffix “a”. Waferfragment 10 a includes a capacitor construction 25 a differing from theconstruction 25 of FIG. 2 in provision of a barrier layer 30 a betweenfirst electrode 26 and dielectric layer 28, rather than betweendielectric layer 28 and second capacitor electrode 32. Barrier layer 30a can include constructions identical to those discussed above withreference to FIG. 1.

[0066]FIG. 3 illustrates yet another alternative embodiment of acapacitor construction. Like numerals from FIG. 1 are utilized whereappropriate, with differences being indicated by the suffix “b” or bydifferent numerals. Wafer fragment 10 b includes a capacitorconstruction 25 b having the first and second capacitor plate 26 and 32,respectively, of the first described embodiment. However, wafer fragment10 b differs from wafer fragment 10 of FIG. 2 in that wafer fragment 10b includes a second barrier layer 40 in addition to the barrier layer30. Barrier layer 40 is provided between first capacitor electrode 26and dielectric layer 28, whereas barrier layer 30 is between secondcapacitor electrode 32 and dielectric layer 28. Barrier layer 40 can beformed by methods identical to those discussed above with reference toFIG. 1 for formation of the barrier layer 30.

[0067] In the embodiments of FIGS. 1-3, the barrier layers arc shown anddescribed as being distinct layers separate from the capacitorelectrodes. It is to be understood, however, that the barrier layers caninclude conductive materials and can accordingly, in such embodiments,be understood to include at least a portion of the capacitorrelectrodes. In particular embodiments an entirety of a capacitorelectrode can include conductive barrier layer materials.

[0068] A system that can be used to perform vapor deposition processes(chemical vapor deposition or atomic layer deposition) of the presentinvention is shown in FIG. 4. The system includes an enclosed vapordeposition chamber 110, in which a vacuum may be created using turbopump 112 and backing pump 114. One or more substrates 116 (e.g.,semiconductor substrates or substrate assemblies) are positioned inchamber 110. A constant nominal temperature is established for substrate116, which can vary depending on the process used. Substrate 116 may beheated, for example, by an electrical resistance heater 118 on whichsubstrate 116 is mounted. Other known methods of heating the substratemay also be utilized.

[0069] In this process, precursor compounds 160 (e.g., a refractorymetal precursor compound and an ether) are stored in vessels 162. Theprecursor compounds are vaporized and separately fed along lines 164 and166 to the deposition chamber 110 using, for example, an inert carriergas 168. A reaction gas 170 may be supplied along line 172 as needed.Also, a purge gas 174, which is often the same as the inert carrier gas168, may be supplied along line 176 as needed. As shown, a series ofvalves 180-185 are opened and closed as required.

[0070] The following examples are offered to further illustrate thevarious specific and preferred embodiments and techniques. It should beunderstood, however, that many variations and modifications may be madewhile remaining within the scope of the present invention, so the scopeof the invention is not intended to be limited by the examples. Unlessspecified otherwise, all percentages shown in the examples arepercentages by weight.

EXAMPLE Example 1. Atomic Layer Deposition of (Hf,Ti)O₂

[0071] A chamber of configuration shown in FIG. 4 was set up withpneumatic valves under computer control to pulse the valves open insequential manner. Two reservoirs connected to the chamber containedTi(NMe₂)₄ and Hf(OC(CH₃)₃)₄ (Strem Chemical, Newburyport, Mass.). Thesubstrate was a silicon wafer having doped poly-silicon as a top layerand was maintained at 150° C. for the deposition.

[0072] Each cycle involved a 5-second pulse of Hf(OC(CH₃)₃)₄ and a5-second pulse of Ti(NMe₂)₄, each separated by a 10-second purge withargon and a 20-second pump down under dynamic vacuum. The precursorswere introduced with helium carrier gas, using mass flow controllers setat 5 sccm. After 400 cycles a (Hf,Ti)O₂ film 180 Å A thick was obtained.The film was nearly 50/50 Hf/Ti based on x-ray photoelectronspectroscopy (XPS) analysis, and had no detectable nitrogen or carbon.

[0073] The complete disclosures of the patents, patent documents, andpublications cited herein are incorporated by reference in theirentirety as if each were individually incorporated. Variousmodifications and alterations to this invention will become apparent tothose skilled in the art without departing from the scope and spirit ofthis invention. It should be understood that this invention is notintended to be unduly limited by the illustrative embodiments andexamples set forth herein and that such examples and embodiments arepresented by way of example only with the scope of the inventionintended to be limited only by the claims set forth herein as follows.

What is claimed is:
 1. A method of manufacturing a semiconductorstructure, the method comprising: providing a semiconductor substrate orsubstrate assembly; providing at least one precursor compound of theformula M¹ _(q)(O)_(x)(OR¹)_(y) (Formula I) and at least one precursorcompound of the formula M²(NR²)_(w)(NR³R⁴)_(z) (Formula II), wherein: M¹and M² are each independently a metal; R¹, R², R³, and R⁴ are eachindependently hydrogen or an organic group; x is 0 to 4; y is 1 to 8; wis 0 to 4; z is 1 to 8; q is 1 or 2; and x, y, z, and w are dependent onthe oxidation states of M¹ and M²; and contacting the precursorcompounds to form a metal oxide layer on one or more surfaces of thesemiconductor substrate or substrate assembly using a vapor depositionprocess.
 2. The method of claim 1 wherein the semiconductor substrate orsubstrate assembly is a silicon wafer.
 3. The method of claim 1 whereinthe metal oxide layer is a dielectric layer.
 4. The method of claim 3wherein the metal oxide dielectric layer comprises two or more differentmetals.
 5. The method of claim 4 wherein the two or more differentmetals are in the form of alloys, solid solutions, or nanolaminates. 6.The method of claim 1 wherein M¹ and M² are each independently selectedfrom the group of metals consisting of Groups 3, 4, 5, 6, 7, 13, 14, andthe lanthanides.
 7. The method of claim 6 wherein M¹ and M² are eachindependently selected from the group of metals consisting of Y, La, Pr,Nd, Gd, Ti, Zr, Hf, Nb, Ta, Si, and Al.
 8. The method of claim 1 whereinthe metal oxide layer has a thickness of about 30 Å to about 80 Å. 9.The method of claim 1 wherein R¹, R², R³, and R⁴ are each independentlyhydrogen or a (C1-C6) organic group.
 10. The method of claim 1 wherein xis 0 to 2 and y is 2 to
 6. 11. The method of claim 1 wherein w is 0 to 2and z is 2 to
 6. 12. The method of claim 1 wherein the metal oxidecomprises two or more different metals.
 13. The method of claim 1wherein M¹ and M² are the same metal.
 14. A method of manufacturing asemiconductor structure, the method comprising: providing asemiconductor substrate or substrate assembly within a depositionchamber; providing at least one precursor compound of the formula M¹_(q)(O)_(x)(OR¹)_(y) (Formula I) and at least one precursor compound ofthe formula M²(NR²)_(w)(NR³R⁴)_(z) (Formula II), wherein: M¹ and M² areeach independently a metal; R¹, R², R³, and R⁴ are each independentlyhydrogen or an organic group; x is 0 to 4; y is 1 to 8; w is 0 to 4; zis 1 to 8; q is 1 or 2; and x, y, z, and w are dependent on theoxidation states of M¹ and M²; vaporizing the precursor compounds toform vaporized precursor compounds; and directing the vaporizedprecursor compounds to the semiconductor substrate or substrate assemblyto form a metal oxide dielectric layer on one or more surfaces of thesemiconductor substrate or substrate assembly.
 15. The method of claim14 wherein the precursor compounds are vaporized in the presence of aninert carrier gas.
 16. The method of claim 14 wherein M¹ and M² are eachindependently selected from the group of metals consisting of Groups 3,4, 5, 6, 7, 13, 14, and the lanthanides.
 17. The method of claim 14wherein vaporizing and directing the precursor compounds is accomplishedusing a chemical vapor deposition process.
 18. The method of claim 17wherein the temperature of the semiconductor substrate or substrateassembly is about 100° C. to about 600° C.
 19. The method of claim 17wherein the semiconductor substrate or substrate assembly is in adeposition chamber having a pressure of about 0.1 torr to about 10 torr.20. The method of claim 14 wherein vaporizing and directing theprecursor compounds is accomplished using an atomic layer depositionprocess comprising a plurality of deposition cycles.
 21. The method ofclaim 20 wherein during the atomic layer deposition process themetal-containing layer is formed by alternately introducing theprecursor compounds during each deposition cycle.
 22. The method ofclaim 20 wherein the temperature of the semiconductor substrate orsubstrate assembly is about 25° C. to about 400° C.
 23. The method ofclaim 20 wherein the semiconductor substrate or substrate assembly is ina deposition chamber having a pressure of about 10⁻⁴ torr to about 1torr.
 24. The method of claim 14 wherein the metal oxide comprises twoor more different metals.
 25. The method of claim 14 wherein M¹ and M²are the same metal.
 26. A method of forming a metal oxide layer on asubstrate, the method comprising: providing a substrate; providing atleast one precursor compound of the formula M¹ _(q)(O)_(x)(OR¹)_(y)(Formula I) and at least one precursor compound of the formulaM²(NR²)_(w)(NR³R⁴)_(z) (Formula II), wherein: M¹ and M² are eachindependently a metal; R¹, R², R³, and R⁴ are each independentlyhydrogen or an organic group; x is 0 to 4; y is 1 to 8; w is 0 to 4; zis 1 to 8; q is 1 or 2; and x, y, z, and w are dependent on theoxidation states of M¹ and M²; and contacting the precursor compounds toform a metal oxide layer on the substrate using a vapor depositionprocess.
 27. The method of claim 26 wherein the substrate is a siliconwafer.
 28. The method of claim 26 wherein the metal oxide layer is adielectric layer.
 29. The method of claim 26 wherein M¹ and M² are eachindependently selected from the group of metals consisting of Groups 3,4, 5, 6, 7, 13, 14, and the lanthanides.
 30. The method of claim 29wherein M¹ and M² are each independently selected from the group ofmetals consisting of Y, La, Pr, Nd, Gd, Ti, Zr, Hf, Nb, Ta, Si, and Al.31. The method of claim 26 wherein the metal oxide layer has a thicknessof about 30 Å to about 80 Å.
 32. The method of claim 26 wherein R¹, R²,R³, and R⁴ are each independently hydrogen or a (C1-C6) organic group.33. The method of claim 26 wherein the metal oxide layer comprises twoor more different metals.
 34. The method of claim 26 wherein M¹ and M²are the same metal.
 35. A method of forming a metal oxide layer on asubstrate, the method comprising: providing a substrate; providing atleast one precursor compound of the formula M¹ _(q)(O)_(x)(OR¹)_(y)(Formula I) and at least one precursor compound of the formulaM²(NR²)_(w)(NR³R⁴)_(z) (Formula II), wherein: M¹ and M² are eachindependently a metal; R¹, R², R³, and R⁴ are each independentlyhydrogen or an organic group; x is 0 to 4; y is 1 to 8; w is 0 to 4; zis 1 to 8; q is 1 or 2; and x, y, z, and w are dependent on theoxidation states of M¹ and M²; vaporizing the precursor compounds toform vaporized precursor compounds; and directing the vaporizedprecursor compounds to the substrate to form a metal oxide layer on thesubstrate.
 36. The method of claim 35 wherein vaporizing and directingthe precursor compounds is accomplished using a chemical vapordeposition process.
 37. The method of claim 35 wherein vaporizing anddirecting the precursor compounds is accomplished using an atomic layerdeposition process comprising a plurality of deposition cycles.
 38. Themethod of claim 35 wherein the metal oxide comprises two or moredifferent metals.
 39. The method of claim 35 wherein M¹ and M² are thesame metal.
 40. A method of manufacturing a memory device structurecomprising: providing a substrate having a first electrode thereon;providing at least one precursor compound of the formula M¹_(q)(O)_(x)(OR¹)_(y) (Formula I) and at least one precursor compound ofthe formula M²(NR²)_(w)(NR³R⁴)_(z) (Formula II), wherein: M¹ and M² areeach independently a metal; R¹, R², R³, and R⁴ are each independentlyhydrogen or an organic group; x is 0 to 4; y is 1 to 8; w is 0 to 4; zis 1 to 8; q is 1 or 2; and x, y, z, and w are dependent on theoxidation states of M¹ and M²; vaporizing the precursor compounds toform vaporized precursor compounds; directing the vaporized precursorcompounds to the substrate to form a metal oxide dielectric layer on thefirst electrode of the substrate; and forming a second electrode on thedielectric layer.
 41. The method of claim 40 wherein vaporizing anddirecting the precursor compounds is accomplished using a chemical vapordeposition process.
 42. The method of claim 40 wherein vaporizing anddirecting the precursor compounds is accomplished using an atomic layerdeposition process comprising a plurality of deposition cycles.
 43. Themethod of claim 42 wherein M¹ and M² are the same metal.
 44. The methodof claim 40 wherein the metal oxide dielectric layer comprises two ormore different metals.
 45. The method of claim 44 wherein the two ormore different metals are in the form of alloys, solid solutions, ornanolaminates.
 46. The method of claim 40 wherein the metal oxidedielectric layer comprises one or more of ZrO₂, HfO₂, Ta₂O₃, Al₂O₃,TiO₂, and an oxide of a lanthanide.
 47. A vapor deposition apparatuscomprising: a vapor deposition chamber having a substrate positionedtherein; one or more vessels comprising one or more precursor compoundsof the formula M¹ _(q)(O)_(x)(OR¹)_(y) (Formula I); and one or morevessels comprising one or more one precursor compounds of the formulaM²(NR²)_(w)(NR³R⁴)_(z) (Formula II), wherein: M¹ and M² are eachindependently a metal; R¹, R², R³, and R⁴ are each independentlyhydrogen or an organic group; x is 0 to 4; y is 1 to 8; w is 0 to 4; zis 1 to 8; q is 1 or 2; and x, y, z, and w are dependent on theoxidation states of M¹ and M².
 48. The apparatus of claim 47 wherein thesubstrate is a silicon wafer.
 49. The apparatus of claim 47 furthercomprising one or more sources of an inert carrier gas for transferringthe precursors to the vapor deposition chamber.